/* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ use api::{FontInstanceFlags, FontSize, BaseFontInstance}; use api::{FontKey, FontRenderMode, FontTemplate}; use api::{ColorU, GlyphIndex, GlyphDimensions, SyntheticItalics}; use api::channel::{unbounded_channel, Receiver, Sender}; use api::units::*; use api::{ImageDescriptor, ImageDescriptorFlags, ImageFormat, DirtyRect}; use crate::internal_types::ResourceCacheError; use crate::platform::font::FontContext; use crate::device::TextureFilter; use crate::gpu_types::UvRectKind; use crate::glyph_cache::{GlyphCache, CachedGlyphInfo, GlyphCacheEntry}; use crate::internal_types::FastHashMap; use crate::resource_cache::CachedImageData; use crate::texture_cache::{TextureCache, TextureCacheHandle, Eviction, TargetShader}; use crate::gpu_cache::GpuCache; use crate::profiler::{self, TransactionProfile}; use malloc_size_of::{MallocSizeOf, MallocSizeOfOps}; use rayon::ThreadPool; use rayon::prelude::*; use euclid::approxeq::ApproxEq; use euclid::size2; use smallvec::SmallVec; use std::cmp; use std::cell::Cell; use std::hash::{Hash, Hasher}; use std::mem; use std::ops::Deref; use std::sync::{Arc, Condvar, Mutex, MutexGuard}; use std::sync::atomic::{AtomicBool, Ordering}; pub static GLYPH_FLASHING: AtomicBool = AtomicBool::new(false); impl FontContexts { /// Get access to the font context associated to the current thread. pub fn lock_current_context(&self) -> MutexGuard { let id = self.current_worker_id(); self.lock_context(id) } pub(in super) fn current_worker_id(&self) -> Option { self.workers.current_thread_index() } } thread_local! { pub static SEED: Cell = Cell::new(0); } // super simple random to avoid dependency on rand fn random() -> u32 { SEED.with(|seed| { seed.set(seed.get().wrapping_mul(22695477).wrapping_add(1)); seed.get() }) } impl GlyphRasterizer { pub fn request_glyphs( &mut self, glyph_cache: &mut GlyphCache, font: FontInstance, glyph_keys: &[GlyphKey], texture_cache: &mut TextureCache, gpu_cache: &mut GpuCache, ) { assert!( self.font_contexts .lock_shared_context() .has_font(&font.font_key) ); let glyph_key_cache = glyph_cache.get_glyph_key_cache_for_font_mut(font.clone()); // select glyphs that have not been requested yet. for key in glyph_keys { if let Some(entry) = glyph_key_cache.try_get(key) { match entry { GlyphCacheEntry::Cached(ref glyph) => { // Skip the glyph if it is already has a valid texture cache handle. if !texture_cache.request(&glyph.texture_cache_handle, gpu_cache) { continue; } // This case gets hit when we already rasterized the glyph, but the // glyph has been evicted from the texture cache. Just force it to // pending so it gets rematerialized. } // Otherwise, skip the entry if it is blank or pending. GlyphCacheEntry::Blank | GlyphCacheEntry::Pending => continue, } } // Increment the total number of glyphs that are pending. This is used to determine // later whether to use worker threads for the remaining glyphs during resolve time. self.pending_glyph_count += 1; self.glyph_request_count += 1; // Find a batch container for the font instance for this glyph. Use get_mut to avoid // cloning the font instance, since this is the common path. match self.pending_glyph_requests.get_mut(&font) { Some(container) => { container.push(*key); // If the batch for this font instance is big enough, kick off an async // job to start rasterizing these glyphs on other threads now. if container.len() == 8 { let glyphs = mem::replace(container, SmallVec::new()); self.flush_glyph_requests( font.clone(), glyphs, true, ); } } None => { // If no batch exists for this font instance, add the glyph to a new one. self.pending_glyph_requests.insert( font.clone(), smallvec![*key], ); } } glyph_key_cache.add_glyph(*key, GlyphCacheEntry::Pending); } } pub fn enable_multithreading(&mut self, enable: bool) { self.enable_multithreading = enable; } /// Internal method to flush a list of glyph requests to a set of worker threads, /// or process on this thread if there isn't much work to do (in which case the /// overhead of processing these on a thread is unlikely to be a performance win). fn flush_glyph_requests( &mut self, font: FontInstance, glyphs: SmallVec<[GlyphKey; 16]>, use_workers: bool, ) { let font_contexts = Arc::clone(&self.font_contexts); let glyph_tx = self.glyph_tx.clone(); self.pending_glyph_jobs += 1; self.pending_glyph_count -= glyphs.len(); fn process_glyph(key: &GlyphKey, font_contexts: &FontContexts, font: &FontInstance) -> GlyphRasterJob { profile_scope!("glyph-raster"); let mut context = font_contexts.lock_current_context(); let mut job = GlyphRasterJob { key: key.clone(), result: context.rasterize_glyph(&font, key), }; if let Ok(ref mut glyph) = job.result { // Sanity check. let bpp = 4; // We always render glyphs in 32 bits RGBA format. assert_eq!( glyph.bytes.len(), bpp * (glyph.width * glyph.height) as usize ); // a quick-and-dirty monochrome over fn over(dst: u8, src: u8) -> u8 { let a = src as u32; let a = 256 - a; let dst = ((dst as u32 * a) >> 8) as u8; src + dst } if GLYPH_FLASHING.load(Ordering::Relaxed) { let color = (random() & 0xff) as u8; for i in &mut glyph.bytes { *i = over(*i, color); } } assert_eq!((glyph.left.fract(), glyph.top.fract()), (0.0, 0.0)); // Check if the glyph has a bitmap that needs to be downscaled. glyph.downscale_bitmap_if_required(&font); // Convert from BGRA8 to R8 if required. In the future we can make it the // backends' responsibility to output glyphs in the desired format, // potentially reducing the number of copies. if glyph.format.image_format().bytes_per_pixel() == 1 { glyph.bytes = glyph.bytes .chunks_mut(4) .map(|pixel| pixel[3]) .collect::>(); } } job } // if the number of glyphs is small, do it inline to avoid the threading overhead; // send the result into glyph_tx so downstream code can't tell the difference. if self.enable_multithreading && use_workers { // spawn an async task to get off of the render backend thread as early as // possible and in that task use rayon's fork join dispatch to rasterize the // glyphs in the thread pool. profile_scope!("spawning process_glyph jobs"); self.workers.spawn(move || { let jobs = glyphs .par_iter() .map(|key: &GlyphKey| process_glyph(key, &font_contexts, &font)) .collect(); glyph_tx.send(GlyphRasterJobs { font, jobs }).unwrap(); }); } else { let jobs = glyphs.iter() .map(|key: &GlyphKey| process_glyph(key, &font_contexts, &font)) .collect(); glyph_tx.send(GlyphRasterJobs { font, jobs }).unwrap(); } } pub fn resolve_glyphs( &mut self, glyph_cache: &mut GlyphCache, texture_cache: &mut TextureCache, gpu_cache: &mut GpuCache, profile: &mut TransactionProfile, ) { profile.start_time(profiler::GLYPH_RESOLVE_TIME); // Work around the borrow checker, since we call flush_glyph_requests below let mut pending_glyph_requests = mem::replace( &mut self.pending_glyph_requests, FastHashMap::default(), ); // If we have a large amount of remaining work to do, spawn to worker threads, // even if that work is shared among a number of different font instances. let use_workers = self.pending_glyph_count >= 8; for (font, pending_glyphs) in pending_glyph_requests.drain() { self.flush_glyph_requests( font, pending_glyphs, use_workers, ); } // Restore this so that we don't heap allocate next frame self.pending_glyph_requests = pending_glyph_requests; debug_assert_eq!(self.pending_glyph_count, 0); debug_assert!(self.pending_glyph_requests.is_empty()); if self.glyph_request_count > 0 { profile.set(profiler::RASTERIZED_GLYPHS, self.glyph_request_count); self.glyph_request_count = 0; } profile_scope!("resolve_glyphs"); // Pull rasterized glyphs from the queue and update the caches. while self.pending_glyph_jobs > 0 { self.pending_glyph_jobs -= 1; // TODO: rather than blocking until all pending glyphs are available // we could try_recv and steal work from the thread pool to take advantage // of the fact that this thread is alive and we avoid the added latency // of blocking it. let GlyphRasterJobs { font, mut jobs } = { profile_scope!("blocking wait on glyph_rx"); self.glyph_rx .recv() .expect("BUG: Should be glyphs pending!") }; // Ensure that the glyphs are always processed in the same // order for a given text run (since iterating a hash set doesn't // guarantee order). This can show up as very small float inaccuracy // differences in rasterizers due to the different coordinates // that text runs get associated with by the texture cache allocator. jobs.sort_by(|a, b| a.key.cmp(&b.key)); let glyph_key_cache = glyph_cache.get_glyph_key_cache_for_font_mut(font); for GlyphRasterJob { key, result } in jobs { let glyph_info = match result { Err(_) => GlyphCacheEntry::Blank, Ok(ref glyph) if glyph.width == 0 || glyph.height == 0 => { GlyphCacheEntry::Blank } Ok(glyph) => { let mut texture_cache_handle = TextureCacheHandle::invalid(); texture_cache.request(&texture_cache_handle, gpu_cache); texture_cache.update( &mut texture_cache_handle, ImageDescriptor { size: size2(glyph.width, glyph.height), stride: None, format: glyph.format.image_format(), flags: ImageDescriptorFlags::empty(), offset: 0, }, TextureFilter::Linear, Some(CachedImageData::Raw(Arc::new(glyph.bytes))), [glyph.left, -glyph.top, glyph.scale], DirtyRect::All, gpu_cache, Some(glyph_key_cache.eviction_notice()), UvRectKind::Rect, Eviction::Auto, TargetShader::Text, ); GlyphCacheEntry::Cached(CachedGlyphInfo { texture_cache_handle, format: glyph.format, }) } }; glyph_key_cache.insert(key, glyph_info); } } // Now that we are done with the critical path (rendering the glyphs), // we can schedule removing the fonts if needed. self.remove_dead_fonts(); profile.end_time(profiler::GLYPH_RESOLVE_TIME); } } #[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd)] #[cfg_attr(feature = "capture", derive(Serialize))] #[cfg_attr(feature = "replay", derive(Deserialize))] pub struct FontTransform { pub scale_x: f32, pub skew_x: f32, pub skew_y: f32, pub scale_y: f32, } // Floats don't impl Hash/Eq/Ord... impl Eq for FontTransform {} impl Ord for FontTransform { fn cmp(&self, other: &Self) -> cmp::Ordering { self.partial_cmp(other).unwrap_or(cmp::Ordering::Equal) } } impl Hash for FontTransform { fn hash(&self, state: &mut H) { // Note: this is inconsistent with the Eq impl for -0.0 (don't care). self.scale_x.to_bits().hash(state); self.skew_x.to_bits().hash(state); self.skew_y.to_bits().hash(state); self.scale_y.to_bits().hash(state); } } impl FontTransform { const QUANTIZE_SCALE: f32 = 1024.0; pub fn new(scale_x: f32, skew_x: f32, skew_y: f32, scale_y: f32) -> Self { FontTransform { scale_x, skew_x, skew_y, scale_y } } pub fn identity() -> Self { FontTransform::new(1.0, 0.0, 0.0, 1.0) } #[allow(dead_code)] pub fn is_identity(&self) -> bool { *self == FontTransform::identity() } pub fn quantize(&self) -> Self { FontTransform::new( (self.scale_x * Self::QUANTIZE_SCALE).round() / Self::QUANTIZE_SCALE, (self.skew_x * Self::QUANTIZE_SCALE).round() / Self::QUANTIZE_SCALE, (self.skew_y * Self::QUANTIZE_SCALE).round() / Self::QUANTIZE_SCALE, (self.scale_y * Self::QUANTIZE_SCALE).round() / Self::QUANTIZE_SCALE, ) } #[allow(dead_code)] pub fn determinant(&self) -> f64 { self.scale_x as f64 * self.scale_y as f64 - self.skew_y as f64 * self.skew_x as f64 } #[allow(dead_code)] pub fn compute_scale(&self) -> Option<(f64, f64)> { let det = self.determinant(); if det != 0.0 { let x_scale = (self.scale_x as f64).hypot(self.skew_y as f64); let y_scale = det.abs() / x_scale; Some((x_scale, y_scale)) } else { None } } #[allow(dead_code)] pub fn pre_scale(&self, scale_x: f32, scale_y: f32) -> Self { FontTransform::new( self.scale_x * scale_x, self.skew_x * scale_y, self.skew_y * scale_x, self.scale_y * scale_y, ) } #[allow(dead_code)] pub fn scale(&self, scale: f32) -> Self { self.pre_scale(scale, scale) } #[allow(dead_code)] pub fn invert_scale(&self, x_scale: f64, y_scale: f64) -> Self { self.pre_scale(x_scale.recip() as f32, y_scale.recip() as f32) } pub fn synthesize_italics(&self, angle: SyntheticItalics, size: f64, vertical: bool) -> (Self, (f64, f64)) { let skew_factor = angle.to_skew(); if vertical { // origin delta to be applied so that we effectively skew around // the middle rather than edge of the glyph let (tx, ty) = (0.0, -size * 0.5 * skew_factor as f64); (FontTransform::new( self.scale_x + self.skew_x * skew_factor, self.skew_x, self.skew_y + self.scale_y * skew_factor, self.scale_y, ), (self.scale_x as f64 * tx + self.skew_x as f64 * ty, self.skew_y as f64 * tx + self.scale_y as f64 * ty)) } else { (FontTransform::new( self.scale_x, self.skew_x - self.scale_x * skew_factor, self.skew_y, self.scale_y - self.skew_y * skew_factor, ), (0.0, 0.0)) } } pub fn swap_xy(&self) -> Self { FontTransform::new(self.skew_x, self.scale_x, self.scale_y, self.skew_y) } pub fn flip_x(&self) -> Self { FontTransform::new(-self.scale_x, self.skew_x, -self.skew_y, self.scale_y) } pub fn flip_y(&self) -> Self { FontTransform::new(self.scale_x, -self.skew_x, self.skew_y, -self.scale_y) } pub fn transform(&self, point: &LayoutPoint) -> DevicePoint { DevicePoint::new( self.scale_x * point.x + self.skew_x * point.y, self.skew_y * point.x + self.scale_y * point.y, ) } pub fn get_subpx_dir(&self) -> SubpixelDirection { if self.skew_y.approx_eq(&0.0) { // The X axis is not projected onto the Y axis SubpixelDirection::Horizontal } else if self.scale_x.approx_eq(&0.0) { // The X axis has been swapped with the Y axis SubpixelDirection::Vertical } else { // Use subpixel precision on all axes SubpixelDirection::Mixed } } } impl<'a> From<&'a LayoutToWorldTransform> for FontTransform { fn from(xform: &'a LayoutToWorldTransform) -> Self { FontTransform::new(xform.m11, xform.m21, xform.m12, xform.m22) } } // Some platforms (i.e. Windows) may have trouble rasterizing glyphs above this size. // Ensure glyph sizes are reasonably limited to avoid that scenario. pub const FONT_SIZE_LIMIT: f32 = 320.0; /// A mutable font instance description. /// /// Performance is sensitive to the size of this structure, so it should only contain /// the fields that we need to modify from the original base font instance. #[derive(Clone, PartialEq, Eq, Debug, Ord, PartialOrd)] #[cfg_attr(feature = "capture", derive(Serialize))] #[cfg_attr(feature = "replay", derive(Deserialize))] pub struct FontInstance { pub base: Arc, pub transform: FontTransform, pub render_mode: FontRenderMode, pub flags: FontInstanceFlags, pub color: ColorU, // The font size is in *device/raster* pixels, not logical pixels. // It is stored as an f32 since we need sub-pixel sizes. pub size: FontSize, } impl Hash for FontInstance { fn hash(&self, state: &mut H) { // Hash only the base instance's key to avoid the cost of hashing // the rest. self.base.instance_key.hash(state); self.transform.hash(state); self.render_mode.hash(state); self.flags.hash(state); self.color.hash(state); self.size.hash(state); } } impl Deref for FontInstance { type Target = BaseFontInstance; fn deref(&self) -> &BaseFontInstance { self.base.as_ref() } } impl MallocSizeOf for FontInstance { fn size_of(&self, _ops: &mut MallocSizeOfOps) -> usize { 0 } } impl FontInstance { pub fn new( base: Arc, color: ColorU, render_mode: FontRenderMode, flags: FontInstanceFlags, ) -> Self { FontInstance { transform: FontTransform::identity(), color, size: base.size, base, render_mode, flags, } } pub fn from_base( base: Arc, ) -> Self { FontInstance { transform: FontTransform::identity(), color: ColorU::new(0, 0, 0, 255), size: base.size, render_mode: base.render_mode, flags: base.flags, base, } } pub fn use_texture_padding(&self) -> bool { self.flags.contains(FontInstanceFlags::TEXTURE_PADDING) } pub fn use_transform_glyphs(&self) -> bool { self.flags.contains(FontInstanceFlags::TRANSFORM_GLYPHS) } pub fn get_alpha_glyph_format(&self) -> GlyphFormat { if self.use_transform_glyphs() { GlyphFormat::TransformedAlpha } else { GlyphFormat::Alpha } } pub fn get_subpixel_glyph_format(&self) -> GlyphFormat { if self.use_transform_glyphs() { GlyphFormat::TransformedSubpixel } else { GlyphFormat::Subpixel } } pub fn disable_subpixel_aa(&mut self) { self.render_mode = self.render_mode.limit_by(FontRenderMode::Alpha); } pub fn disable_subpixel_position(&mut self) { self.flags.remove(FontInstanceFlags::SUBPIXEL_POSITION); } pub fn use_subpixel_position(&self) -> bool { self.flags.contains(FontInstanceFlags::SUBPIXEL_POSITION) && self.render_mode != FontRenderMode::Mono } pub fn get_subpx_dir(&self) -> SubpixelDirection { if self.use_subpixel_position() { let mut subpx_dir = self.transform.get_subpx_dir(); if self.flags.contains(FontInstanceFlags::TRANSPOSE) { subpx_dir = subpx_dir.swap_xy(); } subpx_dir } else { SubpixelDirection::None } } #[allow(dead_code)] pub fn get_subpx_offset(&self, glyph: &GlyphKey) -> (f64, f64) { if self.use_subpixel_position() { let (dx, dy) = glyph.subpixel_offset(); (dx.into(), dy.into()) } else { (0.0, 0.0) } } #[allow(dead_code)] pub fn get_glyph_format(&self) -> GlyphFormat { match self.render_mode { FontRenderMode::Mono | FontRenderMode::Alpha => self.get_alpha_glyph_format(), FontRenderMode::Subpixel => self.get_subpixel_glyph_format(), } } #[allow(dead_code)] pub fn get_extra_strikes(&self, x_scale: f64) -> usize { if self.flags.contains(FontInstanceFlags::SYNTHETIC_BOLD) { let mut bold_offset = self.size.to_f64_px() / 48.0; if bold_offset < 1.0 { bold_offset = 0.25 + 0.75 * bold_offset; } (bold_offset * x_scale).max(1.0).round() as usize } else { 0 } } pub fn synthesize_italics(&self, transform: FontTransform, size: f64) -> (FontTransform, (f64, f64)) { transform.synthesize_italics(self.synthetic_italics, size, self.flags.contains(FontInstanceFlags::VERTICAL)) } #[allow(dead_code)] pub fn get_transformed_size(&self) -> f64 { let (_, y_scale) = self.transform.compute_scale().unwrap_or((1.0, 1.0)); self.size.to_f64_px() * y_scale } } #[repr(u32)] #[derive(Copy, Clone, Hash, PartialEq, Eq, Debug, Ord, PartialOrd)] pub enum SubpixelDirection { None = 0, Horizontal, Vertical, Mixed, } impl SubpixelDirection { // Limit the subpixel direction to what is supported by the glyph format. pub fn limit_by(self, glyph_format: GlyphFormat) -> Self { match glyph_format { GlyphFormat::Bitmap | GlyphFormat::ColorBitmap => SubpixelDirection::None, _ => self, } } pub fn swap_xy(self) -> Self { match self { SubpixelDirection::None | SubpixelDirection::Mixed => self, SubpixelDirection::Horizontal => SubpixelDirection::Vertical, SubpixelDirection::Vertical => SubpixelDirection::Horizontal, } } } #[repr(u8)] #[derive(Hash, Clone, Copy, Debug, Eq, Ord, PartialEq, PartialOrd)] #[cfg_attr(feature = "capture", derive(Serialize))] #[cfg_attr(feature = "replay", derive(Deserialize))] pub enum SubpixelOffset { Zero = 0, Quarter = 1, Half = 2, ThreeQuarters = 3, } impl SubpixelOffset { // Skia quantizes subpixel offsets into 1/4 increments. // Given the absolute position, return the quantized increment fn quantize(pos: f32) -> Self { // Following the conventions of Gecko and Skia, we want // to quantize the subpixel position, such that abs(pos) gives: // [0.0, 0.125) -> Zero // [0.125, 0.375) -> Quarter // [0.375, 0.625) -> Half // [0.625, 0.875) -> ThreeQuarters, // [0.875, 1.0) -> Zero // The unit tests below check for this. let apos = ((pos - pos.floor()) * 8.0) as i32; match apos { 1..=2 => SubpixelOffset::Quarter, 3..=4 => SubpixelOffset::Half, 5..=6 => SubpixelOffset::ThreeQuarters, _ => SubpixelOffset::Zero, } } } impl Into for SubpixelOffset { fn into(self) -> f64 { match self { SubpixelOffset::Zero => 0.0, SubpixelOffset::Quarter => 0.25, SubpixelOffset::Half => 0.5, SubpixelOffset::ThreeQuarters => 0.75, } } } #[derive(Copy, Clone, Hash, PartialEq, Eq, Debug, Ord, PartialOrd)] #[cfg_attr(feature = "capture", derive(Serialize))] #[cfg_attr(feature = "replay", derive(Deserialize))] pub struct GlyphKey(u32); impl GlyphKey { pub fn new( index: u32, point: DevicePoint, subpx_dir: SubpixelDirection, ) -> Self { let (dx, dy) = match subpx_dir { SubpixelDirection::None => (0.0, 0.0), SubpixelDirection::Horizontal => (point.x, 0.0), SubpixelDirection::Vertical => (0.0, point.y), SubpixelDirection::Mixed => (point.x, point.y), }; let sox = SubpixelOffset::quantize(dx); let soy = SubpixelOffset::quantize(dy); assert_eq!(0, index & 0xF0000000); GlyphKey(index | (sox as u32) << 28 | (soy as u32) << 30) } pub fn index(&self) -> GlyphIndex { self.0 & 0x0FFFFFFF } fn subpixel_offset(&self) -> (SubpixelOffset, SubpixelOffset) { let x = (self.0 >> 28) as u8 & 3; let y = (self.0 >> 30) as u8 & 3; unsafe { (mem::transmute(x), mem::transmute(y)) } } } #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)] #[cfg_attr(feature = "capture", derive(Serialize))] #[cfg_attr(feature = "replay", derive(Deserialize))] #[allow(dead_code)] pub enum GlyphFormat { Alpha, TransformedAlpha, Subpixel, TransformedSubpixel, Bitmap, ColorBitmap, } impl GlyphFormat { pub fn ignore_color(self) -> Self { match self { GlyphFormat::ColorBitmap => GlyphFormat::Bitmap, _ => self, } } /// Returns the ImageFormat that a glyph should be stored as in the texture cache. pub fn image_format(&self) -> ImageFormat { // GlyphFormat::Alpha and GlyphFormat::TransformedAlpha should be stored in an R8 // texture, but we ran in to some rendering issues on various platforms after doing so. // So keep using BGRA8 for all glyph formats until those are solved. // See bug 1687554. ImageFormat::BGRA8 } } pub struct RasterizedGlyph { pub top: f32, pub left: f32, pub width: i32, pub height: i32, pub scale: f32, pub format: GlyphFormat, pub bytes: Vec, } impl RasterizedGlyph { #[allow(dead_code)] pub fn downscale_bitmap_if_required(&mut self, font: &FontInstance) { // Check if the glyph is going to be downscaled in the shader. If the scaling is // less than 0.5, that means bilinear filtering can't effectively filter the glyph // without aliasing artifacts. // // Instead of fixing this by mipmapping the glyph cache texture, rather manually // produce the appropriate mip level for individual glyphs where bilinear filtering // will still produce acceptable results. match self.format { GlyphFormat::Bitmap | GlyphFormat::ColorBitmap => {}, _ => return, } let (x_scale, y_scale) = font.transform.compute_scale().unwrap_or((1.0, 1.0)); let upscaled = x_scale.max(y_scale) as f32; let mut new_scale = self.scale; if new_scale * upscaled <= 0.0 { return; } let mut steps = 0; while new_scale * upscaled <= 0.5 { new_scale *= 2.0; steps += 1; } // If no mipping is necessary, just bail. if steps == 0 { return; } // Calculate the actual size of the mip level. let new_width = (self.width as usize + (1 << steps) - 1) >> steps; let new_height = (self.height as usize + (1 << steps) - 1) >> steps; let mut new_bytes: Vec = Vec::with_capacity(new_width * new_height * 4); // Produce destination pixels by applying a box filter to the source pixels. // The box filter corresponds to how graphics drivers may generate mipmaps. for y in 0 .. new_height { for x in 0 .. new_width { // Calculate the number of source samples that contribute to the destination pixel. let src_y = y << steps; let src_x = x << steps; let y_samples = (1 << steps).min(self.height as usize - src_y); let x_samples = (1 << steps).min(self.width as usize - src_x); let num_samples = (x_samples * y_samples) as u32; let mut src_idx = (src_y * self.width as usize + src_x) * 4; // Initialize the accumulator with half an increment so that when later divided // by the sample count, it will effectively round the accumulator to the nearest // increment. let mut accum = [num_samples / 2; 4]; // Accumulate all the contributing source sampless. for _ in 0 .. y_samples { for _ in 0 .. x_samples { accum[0] += self.bytes[src_idx + 0] as u32; accum[1] += self.bytes[src_idx + 1] as u32; accum[2] += self.bytes[src_idx + 2] as u32; accum[3] += self.bytes[src_idx + 3] as u32; src_idx += 4; } src_idx += (self.width as usize - x_samples) * 4; } // Finally, divide by the sample count to get the mean value for the new pixel. new_bytes.extend_from_slice(&[ (accum[0] / num_samples) as u8, (accum[1] / num_samples) as u8, (accum[2] / num_samples) as u8, (accum[3] / num_samples) as u8, ]); } } // Fix the bounds for the new glyph data. self.top /= (1 << steps) as f32; self.left /= (1 << steps) as f32; self.width = new_width as i32; self.height = new_height as i32; self.scale = new_scale; self.bytes = new_bytes; } } pub struct FontContexts { // These worker are mostly accessed from their corresponding worker threads. // The goal is that there should be no noticeable contention on the mutexes. worker_contexts: Vec>, // This worker should be accessed by threads that don't belong to the thread pool // (in theory that's only the render backend thread so no contention expected either). shared_context: Mutex, // Stored here as a convenience to get the current thread index. #[allow(dead_code)] workers: Arc, locked_mutex: Mutex, locked_cond: Condvar, } impl FontContexts { /// Get access to any particular font context. /// /// The id is ```Some(i)``` where i is an index between 0 and num_worker_contexts /// for font contexts associated to the thread pool, and None for the shared /// global font context for use outside of the thread pool. pub fn lock_context(&self, id: Option) -> MutexGuard { match id { Some(index) => self.worker_contexts[index].lock().unwrap(), None => self.shared_context.lock().unwrap(), } } /// Get access to the font context usable outside of the thread pool. pub fn lock_shared_context(&self) -> MutexGuard { self.shared_context.lock().unwrap() } // number of contexts associated to workers pub fn num_worker_contexts(&self) -> usize { self.worker_contexts.len() } } pub trait AsyncForEach { fn async_for_each) + Send + 'static>(&self, f: F); } impl AsyncForEach for Arc { fn async_for_each) + Send + 'static>(&self, f: F) { // Reset the locked condition. let mut locked = self.locked_mutex.lock().unwrap(); *locked = false; // Arc that can be safely moved into a spawn closure. let font_contexts = self.clone(); // Spawn a new thread on which to run the for-each off the main thread. self.workers.spawn(move || { // Lock the shared and worker contexts up front. let mut locks = Vec::with_capacity(font_contexts.num_worker_contexts() + 1); locks.push(font_contexts.lock_shared_context()); for i in 0 .. font_contexts.num_worker_contexts() { locks.push(font_contexts.lock_context(Some(i))); } // Signal the locked condition now that all contexts are locked. *font_contexts.locked_mutex.lock().unwrap() = true; font_contexts.locked_cond.notify_all(); // Now that everything is locked, proceed to processing each locked context. for context in locks { f(context); } }); // Wait for locked condition before resuming. Safe to proceed thereafter // since any other thread that needs to use a FontContext will try to lock // it first. while !*locked { locked = self.locked_cond.wait(locked).unwrap(); } } } pub struct GlyphRasterizer { #[allow(dead_code)] workers: Arc, font_contexts: Arc, /// The current number of individual glyphs waiting in pending batches. pending_glyph_count: usize, /// The current number of glyph request jobs that have been kicked to worker threads. pending_glyph_jobs: usize, /// The number of glyphs requested this frame. glyph_request_count: usize, /// A map of current glyph request batches. pending_glyph_requests: FastHashMap>, // Receives the rendered glyphs. glyph_rx: Receiver, glyph_tx: Sender, // We defer removing fonts to the end of the frame so that: // - this work is done outside of the critical path, // - we don't have to worry about the ordering of events if a font is used on // a frame where it is used (although it seems unlikely). fonts_to_remove: Vec, // Defer removal of font instances, as for fonts. font_instances_to_remove: Vec, // Whether to parallelize glyph rasterization with rayon. enable_multithreading: bool, } impl GlyphRasterizer { pub fn new(workers: Arc) -> Result { let (glyph_tx, glyph_rx) = unbounded_channel(); let num_workers = workers.current_num_threads(); let mut contexts = Vec::with_capacity(num_workers); let shared_context = FontContext::new()?; for _ in 0 .. num_workers { contexts.push(Mutex::new(FontContext::new()?)); } let font_context = FontContexts { worker_contexts: contexts, shared_context: Mutex::new(shared_context), workers: Arc::clone(&workers), locked_mutex: Mutex::new(false), locked_cond: Condvar::new(), }; Ok(GlyphRasterizer { font_contexts: Arc::new(font_context), pending_glyph_jobs: 0, pending_glyph_count: 0, glyph_request_count: 0, glyph_rx, glyph_tx, workers, fonts_to_remove: Vec::new(), font_instances_to_remove: Vec::new(), enable_multithreading: true, pending_glyph_requests: FastHashMap::default(), }) } pub fn add_font(&mut self, font_key: FontKey, template: FontTemplate) { self.font_contexts.async_for_each(move |mut context| { context.add_font(&font_key, &template); }); } pub fn delete_font(&mut self, font_key: FontKey) { self.fonts_to_remove.push(font_key); } pub fn delete_font_instance(&mut self, instance: &FontInstance) { self.font_instances_to_remove.push(instance.clone()); } pub fn prepare_font(&self, font: &mut FontInstance) { FontContext::prepare_font(font); // Quantize the transform to minimize thrashing of the glyph cache, but // only quantize the transform when preparing to access the glyph cache. // This way, the glyph subpixel positions, which are calculated before // this, can still use the precise transform which is required to match // the subpixel positions computed for glyphs in the text run shader. font.transform = font.transform.quantize(); } pub fn get_glyph_dimensions( &mut self, font: &FontInstance, glyph_index: GlyphIndex, ) -> Option { let glyph_key = GlyphKey::new( glyph_index, DevicePoint::zero(), SubpixelDirection::None, ); self.font_contexts .lock_shared_context() .get_glyph_dimensions(font, &glyph_key) } pub fn get_glyph_index(&mut self, font_key: FontKey, ch: char) -> Option { self.font_contexts .lock_shared_context() .get_glyph_index(font_key, ch) } fn remove_dead_fonts(&mut self) { if self.fonts_to_remove.is_empty() && self.font_instances_to_remove.is_empty() { return } profile_scope!("remove_dead_fonts"); let fonts_to_remove = mem::replace(&mut self.fonts_to_remove, Vec::new()); let font_instances_to_remove = mem::replace(& mut self.font_instances_to_remove, Vec::new()); self.font_contexts.async_for_each(move |mut context| { for font_key in &fonts_to_remove { context.delete_font(font_key); } for instance in &font_instances_to_remove { context.delete_font_instance(instance); } }); } #[cfg(feature = "replay")] pub fn reset(&mut self) { //TODO: any signals need to be sent to the workers? self.pending_glyph_jobs = 0; self.pending_glyph_count = 0; self.glyph_request_count = 0; self.fonts_to_remove.clear(); self.font_instances_to_remove.clear(); } } trait AddFont { fn add_font(&mut self, font_key: &FontKey, template: &FontTemplate); } impl AddFont for FontContext { fn add_font(&mut self, font_key: &FontKey, template: &FontTemplate) { match *template { FontTemplate::Raw(ref bytes, index) => { self.add_raw_font(font_key, bytes.clone(), index); } FontTemplate::Native(ref native_font_handle) => { self.add_native_font(font_key, (*native_font_handle).clone()); } } } } #[allow(dead_code)] pub(in crate::glyph_rasterizer) struct GlyphRasterJob { key: GlyphKey, result: GlyphRasterResult, } #[allow(dead_code)] pub enum GlyphRasterError { LoadFailed, } #[allow(dead_code)] pub type GlyphRasterResult = Result; #[derive(Debug, Copy, Clone, Eq, Hash, PartialEq)] #[cfg_attr(feature = "capture", derive(Serialize))] #[cfg_attr(feature = "replay", derive(Deserialize))] pub struct GpuGlyphCacheKey(pub u32); #[allow(dead_code)] struct GlyphRasterJobs { font: FontInstance, jobs: Vec, } #[cfg(test)] mod test_glyph_rasterizer { pub const FORMAT: api::ImageFormat = api::ImageFormat::BGRA8; #[test] fn rasterize_200_glyphs() { // This test loads a font from disc, the renders 4 requests containing // 50 glyphs each, deletes the font and waits for the result. use rayon::ThreadPoolBuilder; use std::fs::File; use std::io::Read; use crate::texture_cache::TextureCache; use crate::glyph_cache::GlyphCache; use crate::gpu_cache::GpuCache; use crate::profiler::TransactionProfile; use api::{FontKey, FontInstanceKey, FontSize, FontTemplate, FontRenderMode, IdNamespace, ColorU}; use api::units::DevicePoint; use std::sync::Arc; use crate::glyph_rasterizer::{FontInstance, BaseFontInstance, GlyphKey, GlyphRasterizer}; let worker = ThreadPoolBuilder::new() .thread_name(|idx|{ format!("WRWorker#{}", idx) }) .build(); let workers = Arc::new(worker.unwrap()); let mut glyph_rasterizer = GlyphRasterizer::new(workers).unwrap(); let mut glyph_cache = GlyphCache::new(); let mut gpu_cache = GpuCache::new_for_testing(); let mut texture_cache = TextureCache::new_for_testing(2048, FORMAT); let mut font_file = File::open("../wrench/reftests/text/VeraBd.ttf").expect("Couldn't open font file"); let mut font_data = vec![]; font_file .read_to_end(&mut font_data) .expect("failed to read font file"); let font_key = FontKey::new(IdNamespace(0), 0); glyph_rasterizer.add_font(font_key, FontTemplate::Raw(Arc::new(font_data), 0)); let font = FontInstance::from_base(Arc::new(BaseFontInstance { instance_key: FontInstanceKey(IdNamespace(0), 0), font_key, size: FontSize::from_f32_px(32.0), bg_color: ColorU::new(0, 0, 0, 0), render_mode: FontRenderMode::Subpixel, flags: Default::default(), synthetic_italics: Default::default(), platform_options: None, variations: Vec::new(), })); let subpx_dir = font.get_subpx_dir(); let mut glyph_keys = Vec::with_capacity(200); for i in 0 .. 200 { glyph_keys.push(GlyphKey::new( i, DevicePoint::zero(), subpx_dir, )); } for i in 0 .. 4 { glyph_rasterizer.request_glyphs( &mut glyph_cache, font.clone(), &glyph_keys[(50 * i) .. (50 * (i + 1))], &mut texture_cache, &mut gpu_cache, ); } glyph_rasterizer.delete_font(font_key); glyph_rasterizer.resolve_glyphs( &mut glyph_cache, &mut TextureCache::new_for_testing(4096, FORMAT), &mut gpu_cache, &mut TransactionProfile::new(), ); } #[test] fn rasterize_large_glyphs() { // This test loads a font from disc and rasterize a few glyphs with a size of 200px to check // that the texture cache handles them properly. use rayon::ThreadPoolBuilder; use std::fs::File; use std::io::Read; use crate::texture_cache::TextureCache; use crate::glyph_cache::GlyphCache; use crate::gpu_cache::GpuCache; use crate::profiler::TransactionProfile; use api::{FontKey, FontInstanceKey, FontSize, FontTemplate, FontRenderMode, IdNamespace, ColorU}; use api::units::DevicePoint; use std::sync::Arc; use crate::glyph_rasterizer::{FontInstance, BaseFontInstance, GlyphKey, GlyphRasterizer}; let worker = ThreadPoolBuilder::new() .thread_name(|idx|{ format!("WRWorker#{}", idx) }) .build(); let workers = Arc::new(worker.unwrap()); let mut glyph_rasterizer = GlyphRasterizer::new(workers).unwrap(); let mut glyph_cache = GlyphCache::new(); let mut gpu_cache = GpuCache::new_for_testing(); let mut texture_cache = TextureCache::new_for_testing(2048, FORMAT); let mut font_file = File::open("../wrench/reftests/text/VeraBd.ttf").expect("Couldn't open font file"); let mut font_data = vec![]; font_file .read_to_end(&mut font_data) .expect("failed to read font file"); let font_key = FontKey::new(IdNamespace(0), 0); glyph_rasterizer.add_font(font_key, FontTemplate::Raw(Arc::new(font_data), 0)); let font = FontInstance::from_base(Arc::new(BaseFontInstance { instance_key: FontInstanceKey(IdNamespace(0), 0), font_key, size: FontSize::from_f32_px(200.0), bg_color: ColorU::new(0, 0, 0, 0), render_mode: FontRenderMode::Subpixel, flags: Default::default(), synthetic_italics: Default::default(), platform_options: None, variations: Vec::new(), })); let subpx_dir = font.get_subpx_dir(); let mut glyph_keys = Vec::with_capacity(10); for i in 0 .. 10 { glyph_keys.push(GlyphKey::new( i, DevicePoint::zero(), subpx_dir, )); } glyph_rasterizer.request_glyphs( &mut glyph_cache, font.clone(), &glyph_keys, &mut texture_cache, &mut gpu_cache, ); glyph_rasterizer.delete_font(font_key); glyph_rasterizer.resolve_glyphs( &mut glyph_cache, &mut TextureCache::new_for_testing(4096, FORMAT), &mut gpu_cache, &mut TransactionProfile::new(), ); } #[test] fn test_subpx_quantize() { use crate::glyph_rasterizer::SubpixelOffset; assert_eq!(SubpixelOffset::quantize(0.0), SubpixelOffset::Zero); assert_eq!(SubpixelOffset::quantize(-0.0), SubpixelOffset::Zero); assert_eq!(SubpixelOffset::quantize(0.1), SubpixelOffset::Zero); assert_eq!(SubpixelOffset::quantize(0.01), SubpixelOffset::Zero); assert_eq!(SubpixelOffset::quantize(0.05), SubpixelOffset::Zero); assert_eq!(SubpixelOffset::quantize(0.12), SubpixelOffset::Zero); assert_eq!(SubpixelOffset::quantize(0.124), SubpixelOffset::Zero); assert_eq!(SubpixelOffset::quantize(0.125), SubpixelOffset::Quarter); assert_eq!(SubpixelOffset::quantize(0.2), SubpixelOffset::Quarter); assert_eq!(SubpixelOffset::quantize(0.25), SubpixelOffset::Quarter); assert_eq!(SubpixelOffset::quantize(0.33), SubpixelOffset::Quarter); assert_eq!(SubpixelOffset::quantize(0.374), SubpixelOffset::Quarter); assert_eq!(SubpixelOffset::quantize(0.375), SubpixelOffset::Half); assert_eq!(SubpixelOffset::quantize(0.4), SubpixelOffset::Half); assert_eq!(SubpixelOffset::quantize(0.5), SubpixelOffset::Half); assert_eq!(SubpixelOffset::quantize(0.58), SubpixelOffset::Half); assert_eq!(SubpixelOffset::quantize(0.624), SubpixelOffset::Half); assert_eq!(SubpixelOffset::quantize(0.625), SubpixelOffset::ThreeQuarters); assert_eq!(SubpixelOffset::quantize(0.67), SubpixelOffset::ThreeQuarters); assert_eq!(SubpixelOffset::quantize(0.7), SubpixelOffset::ThreeQuarters); assert_eq!(SubpixelOffset::quantize(0.78), SubpixelOffset::ThreeQuarters); assert_eq!(SubpixelOffset::quantize(0.874), SubpixelOffset::ThreeQuarters); assert_eq!(SubpixelOffset::quantize(0.875), SubpixelOffset::Zero); assert_eq!(SubpixelOffset::quantize(0.89), SubpixelOffset::Zero); assert_eq!(SubpixelOffset::quantize(0.91), SubpixelOffset::Zero); assert_eq!(SubpixelOffset::quantize(0.967), SubpixelOffset::Zero); assert_eq!(SubpixelOffset::quantize(0.999), SubpixelOffset::Zero); assert_eq!(SubpixelOffset::quantize(-1.0), SubpixelOffset::Zero); assert_eq!(SubpixelOffset::quantize(1.0), SubpixelOffset::Zero); assert_eq!(SubpixelOffset::quantize(1.5), SubpixelOffset::Half); assert_eq!(SubpixelOffset::quantize(-1.625), SubpixelOffset::Half); assert_eq!(SubpixelOffset::quantize(-4.33), SubpixelOffset::ThreeQuarters); } }